Merge pull request #4 from linux-kernel-labs-zh/hanyujie2002-patch-3

Update language again

Documentation/conf.py

@@ -189,7 +189,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = 'zh-CN'
+language = 'zh_CN'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used: